Detergent oil composition and the method for its preparation



Patented Jan. 22, 1952 DETERGENT OILCOMPOSITIONAND THE METHOD'FORF ITS PREPARATION I .Elmer W. Brennan and Norman D. Williams, Chicago, 111., assignors to The Pure Oil Company, Chicago, 111., a corporationof Ohio 7 No Drawing, ApplicationOctober 16, 1948, Serial No. 55,008.

This invention relates to lubricants andjmore particularly, to lubricants having detergent qualities.- Specifically, it concerns the method of preparing a new additive for enhancin the detergent characteristics ofan oil.

It is a fundamental object. of the instant in vention to provide a new method-ofpreparing a phosphorized-sulfurized fatty additive having enhanced detergent qualities and containing amounts ofmetals substantially greater than it has *previo'usly been possible to incorporate i into the additive.

It is afur-ther objectof the invention-to provide a new "sulfurized phosphorized detergent lubrieating composition containing 'phosphorus,=-sulfur and more than one metal.

It is afurther objectof the invention-topmvide anew method of preparing sulfurized phosphorized' lubricatin oil compositions containing detergent-metals.

It is a further object of'the invention to provide a method of incorporating a relatively large amount ofa detergent metal intoa sulfurizedphosphorized lubricating oiladditive concentrate.

Other objects and'advantages of the invention will in part be obvious and in part appearhereinafter;

We have discovered-that an improved lubrieating -oil additive can be prepared ifa fatty material; for example, oleic acid, is -first neutralized with a metallic hydroxide or oxide, preferably one whichimparts a'specific desired-property I to the additive, then reacted with a Y ph'osphorizing-sulfurizing reagent until the reaction is complete-and any functional group produced by the phosphorizing-sulfurizing-reagent subsequently reacted with the same or a different metal oxide "or hydroxide, thereby to give a'compound which has valuable -characteristics,- the chief ofwhich'are its detergent qualities-and-high metarcontent.

Typical fatty materials which can be used in our process include fatty acidshaving about 12 to 30 carbon atoms or-more and alsoha-ving a functional group reactive with'a sulfide of phosphorus, such as hydroxy stearic, oleic, ricinole'ic acids, oxidized petroleum hydrocarbons containing both hydroxy and olefinic acids and fatty acid mixtures derived from natural oils, such as cornseed, rapeseed, linseed,qsperm and castoroils. The natural oils which are the sources of these various fatty-acids-themselves are also useful starting materials:

The materials useful for'neutralizationi'purposesmay-be any which will put, into the com- 18 Claims. (Cl. 260399) 2 pound a metallwhich will impart desirable :prop: erties and thus would include the metals, oxides, hydroxides and carbonates.

The purpose of using the oxide or the. hydroxide of a metal in the saponification reaction or sub.- sequent-neutralization is to introducev metal into the fatty'material used as the startingmaterial. Where the oxide or hydroxide is soluble .inwwater, theoretically athleast, an aqueoussolution thereof could be used, but inasmuch as the tern, peratures. involved in thesaponification reaction are such that water is normally allowedto distill off, the use of aqueous solutionsis avoided. Similarly, where a high molecular weight fatty acid, such as oleic is used as the startin material, the initial saponification could be carried out by reaction of the acid with the metal. However, as noted, convenience dictates the use of an'oxide or a hydroxide. Ingeneral the oxides and hydroxides of the saponifying metals can be used interchangeably. Thus, in the saponification of the fatty material or the subsequentneutralization of the phosphorized-sulfurized salt, the active ingredient in the reaction is the metal oxide and those cases in which the hydroxide is used are the full equivalent thereof; but the hydroxide is used as a matter of convenience. Thus, barium imparts good detergency to the product; Zinc imparts good anti-oxidant properties. An additive having good detergent and anti-oxidant qualities can, therefore, be made by neutralizing the fatty starting material-with barium oxide-or hydroxide, sulfurizing and phosphorizingwith any phosphorizingand sulfurizing agents, such .as phosphorus, sulfur, their oxides and chlorides, phosphorus sesquisulfide and phosphorusepentasulfide, and:finally neutralizing with Zinc oxide or hydroxide. Thus, to impart specific detergent and anti-oxidant properties to the additive; various combinations of neutralizin materialscan be used, such as hydroxides and oxides of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt as well as various amines;

The following examples illustrate a few typical preparations:

Example I .-Two hundred (200) grams of ole'ic acid dissolved in800 grams of /l80 viscosity Mid-Continent solvent refined oil was heated withagita-tion to 275 to; 300 F1 The principal quality desired of the diluent oil or-"reaction mediumis that it should be inert and unreactive with the phosphorizing and sulfurizing agents used in the reaction; Certain hydrocarbon solventsrlike toluene are useful in the operation be- "cause they'are free of-reactive materials: To this of 250 F. without employing external heat. Un-

der these conditions, the phosphorization-sulfurization reaction is quite exothermic and the technique of aerating a mixture during reaction thereof reduces or eliminates the necessity for the application of external heat. Within a period of about minutes, the reaction was completed as evidenced by the cessation of fuming of the reaction mixture. It is also to be noted that upon d completion of the phosphorization-sulfurization reaction, the temperature sustained by the heat of the reaction drops ofi. This characteristic of the reaction can be used as a good index of the time of completion. After reaction of the neutralized oleic acid with phosphorus sesquisulfide, the temperature was raised to 275 to 300 F. and 54 grams of barium hydroxide octahydrate was added to the solution. Heating was continued for half an hour after the final addition of the hydroxide. The product was filtered to remove solids and the composition by weight of the filtrate was as follows:

Actual (By analysis) Theoretical Per Cent Btu-2.19 2. 23 1.35 0. 58 Per Cent P0.67 0.75

When expressed in terms of active components, the composition appears as follows:

Actual Theorcti cal Per Cent Ba9.27 9. 33 Per Cent Ca4.87 5. 65 Per Cent 8-2.20 2. 41 Per Cent P2.83 3. 11 Per Cent Oleic Acid-80.83"..- 79. 50

cium to introduce 9.27 per cent barium into the molecule. Since only 0.78 per cent calcium was lost from the theoreticalvalue of 5.65 per cent, the barium must have entered the molecule at another point, viz., the thiophosphorus group. Some of the loss of calcium was undoubtedly due to hydrolysis during the second neutralization and/or removal in the course of the sulfurizingphosphorizing reaction.

Sufiicient of the material was blended with a Mid-Continent solvent refined oil SAE-IO, to give a total metal content of 0.27 per cent. The finished blend gave no evidence of separation after storage of samples at room temperature and F. for 10 days.

Example II .--Following the procedure outlined in Example I, calcium oleate was prepared and to it 14 grams of phosphorus pentasulfide per hundred grams of oleic acid was added and reacted at about 300 F. for two hours. At the end of this time, there was no evolution of hydrogen sulfide, indicating that the reaction was complete. At this point 37 grams of barium hydroxide octahydrate was added while the reaction mixture was held at 275 to 300 F. Heating was continued for a half hour after the final addition of the hydroxide. Two per cent filter aid was then added, the product was filtered to remove solids and analyzed. The composition was as follows:

Actual (By Analysis) Theoretical Per Cent BEL-1.47 1.52 Per Cent (la-1.12 1. 34 Per Cent P-0.78 0. 64 Per Cent S-l.55 1.90

In terms of active ingredients, the composition would be:

One of the tests of the stability of any hydrocarbon product is its resistance to deterioration in storage. For example, samples of a finished blend consisting of Mid-Continent solvent refined oil and the above additive showed no evidence of deterioration after prolonged storage at room temperature and 30 F.

The composition has the advantage that it can be made to show a high degree of detergency by incorporating into the starting material any of a wide variety of metals, namely, barium, strontium, other alkaline earth materials, and also tin, zinc, lead and nickel.

By the proper choice of metals, an additive possessing specific difierent functions in a single molecule or composition can be prepared. For example, if barium oleate is treated with a sulfide of phosphorus and then the thiophosphorus material neutralized with barium oxide or hydroxide, the product will have a high degree of detergency and a metal content in excess of the stoichiometric equivalent of the starting acid. However,

if zinc oxide were to be used in place of barium hydroxide to neutralize the thiophosphorus material, a two-purpose additive as a single compound would be prepared. That is, the barium soap portion of the molecule would impart good detergency properties, whereas the zinc-sulfurphosphorus would impart anti-oxidant properties. Thus, a detergent additive made in accordance with the invention can contain the same combination of ingredients, but can display different properties depending upon the order in which they were combined. In the preparation of a series of additives, it was found that zinc, for example, could be used in either the first saponification step or in the subsequent neutralization and that the efiect of moderating the viscosity increase of the oil blend after use was retained.

This phase of the composition is illustrated by the following compounds made in accordance with the procedure described:

No. l--Barium salt of barium oleate. No. 2Zinc salt of barium oleate. No. 3Barium salt of zinc oleate.

Composition No. 1 is the barium salt of sulfurcarrying capacity. 7

There is a limit to the amountof metalwhich panbe added in the second neutralizationreaction' carried out inaccordance with theprocess j described. Thus referringto Example ILwhen 1.55 per cent barium'was added -to *the' compound, a moderately viscous liquidpr'oduct was obtained.

When the percentage "of barium was increased to 2, a very viscous productresulted. "When the "percentage was increased to a level between 2.00

and 2.25 per cent, the productgelled. This gel is rived. Similarly, there are limiting percentages,

above which gel-formationwill take place for each metal or combination of metals.

As the'initial fatty acid reagent, any compound which hasa carboxyl group plus a functional group which'isreactive'witha sulfide of phos- .-phorus can be used. Examples of such possible compounds are hydroxy fatty acids, such as hydroxy stearic' acid, 'olefinic materials, or oxidized petroleum fractions which contain both hydroxy acids and keto acids. It is not necessarythat the starting material beafreeacid for anyof the natural fats or oils' which give an acid contain- "ing thedesired'functional groupcan be used.

Thus, the various oils, fats and waxes,"such as 1 sperm oil, castor'oil, linseed oil; rapeseed oil; fats containing unsaturated acids, degras, andthe like can beemployed. H

An example of another composition'prepared inaccordance with the invention is the following:

EmamplefIIL- 'Six hundred (600) i grams of neutral degras, commonly known aswool' grease or Wool wax, washeate'd to 300 to 325 F. with stirring. The wool fat was then saponifled with 150 grams of barium hydroxide octahydrate. As

thesaponification proceeded, the reaction mixture 1 became extremely viscous. 'tionof the hydroxide hadbeen made, the tem- After the final addiperature was dropped to230 F. and 45 grams 1 ofphosphorussesquisulfide added. Air was passed into the reaction mixture at a rate sufiicient to maintain a temperature of 240 F. without the use of external heat. Within a few minutes, the

i contents ofthe reaction flask became more fiuid. When the sulfide had been completely reacted as evidenced by a cessation of fuming and a drop in temperature, in spite of a more rapid flow of air,

1200 grams of 160/180 neutral Mid-Continent solvent refined-oil was added tothe reaction product. When the complete solution had taken place, 168 grams of bariumhydroxide octahydrate was added at 275 to 300 F. to neutralize the sulfurphosphorus acidity. The filteredproduct contained 7.0. per cent barium determined by the 'sulfatedresidue method. This figure exceeded the theoretical. one of 6.4"per cent, but the dis-,

" "crepancycan'be attributedto experimental error. A

side.

Thedetergent'qualities of the compcsitionwere "tested for 120 hours under the Caterpillar diesel 'L-l test procedure (CRC designation L-l545). Though normally the Caterpillar diesel L-l test lasts 480 hours, an approximate measure of the eifectiveness of the detergent can be determined in 120 hours. That is, the detergency' of an: oil can be measured on the degree of engine cleanliness maintained in 120 hours of the test.

The following examples summarize the results of several tests conducted to evaluate the detergent composition:

Example 1.-A blend of an SAE-30 Mid-Con- -tinent sol-vent refined oil containing 0.5 percent of an anti-corrosion additive known commercially as Santclube 394-C was subjected to 120.hours of test following theCaterpillar Lsl diesel test procedure and evaluated for detergency on the basis of 'an examination of thering grooves, lands andskirtof the engine pistons after the test. The ring grooves showed heavy .carbon' and black varnish deposits, the lands sho-wedxrelatively heavy and medium deposition of black varnish and the skirt showed varnish above the pin-boss and on the side oppositefrom the thrust In view of-the'condition of the parts of the piston, the over-all rating of the oilwas such that the oil was considered a failure.

Example 2.A composition J consisting of an SAE -BO Mid-Continent solvent refined oil including 1 per cent of Santolube 394.-C" as a corrosion inhibitor and 0.27 per cent by weight of metal in the form of the double salti additive was subjected to 120 hours of test following .the

r Caterpillar L1 diesel test. procedure. 1 The additiveused was the barium salt of zinc oleate made from oleic acid in accordance with the procedure described in Example II, wherein zinc oxide was used to neutralize oleic' acid, the product pnosphorized and sulfurized and the acidity thus developed neutralized with barium hydroxide. 'After 120 hours of the Caterpillar. L.-1 diesel test, the engine was examined for ltheconditionhof the ring grooves, lands and skirt. The. ring grooves showediight "deposits of soft carbon, light deposits of clear varnish -and the fourth ring groove was clean. The lands had relatively light coatings of dark varnish and the skirt=!of the piston was clean. In-view'of the condition of the ring grooves, landsand sl:irt,-tl1edetergent combination-was considered eiiective in maintaining engine cleanliness.

-E'mample 3.A similar test" was' conducted using a composition consisting of an" SAE -30 Mid-Continent"solvent refined oil containing 1 per cent of Santolube 39443 and 0.27 per cent by weight of barium from the *double 'barium salt of phosphorizedsuliurized-wool greasernade in accordance with the procedure'described in Example III. "After l20hours of test under the Caterpillar Ll diesel test procedure, thepistcns were examined for their" condition. Thering grooves showed a moderately light carbon deposit and a moderate varnishjdep osit. The landsbetween the grooves showed light .co'atingsiof varnish onlonly the first the othersbeing'clean.

, The skirt was clean. On the basis ofth'ese re- "or the barium salt ofthe zinc saponified wool "grease prepared in accordance with 'theproce- 7 dure described in Example III was subjected 120 hours to the Caterpillar L-l diesel test procedure. This composition is typical of those which can be prepared from a-fatty material which has been sulfurized and phosphorized and reacted to form the salt. After the 120 hour run, the ring grooves, lands and skirt of the piston were examined for their condition. Of the ring grooves, only the first showed a slight carbon deposit on the thrust side, the rest was clean. The remaining ring grooves were also clean. The lands had a light varnish coating on a few areas on the first, and the remainder were clean. The skirt was clean. On the basis of these results, the detergent combination was rated exceptionally good.

The Santolube 394- used in the tests reported in the examples is a sulfurized-phosphorized terpene-like material commonly used as an anti-corrosive additive in oils. Its properties are: viscosity at 210 F., 145 SUS; specific gravity,

1.03; phosphorus content, 4.75 per cent; sulfur through 4, with no additive, was subjected to- 120 hours of test in a diesel engine operated in accordance with the L-1 diesel test procedure used in Examples 1 through 4. Following the test, the pistons were examined for their condition in order to provide a basis for rating the oil. The crown was evenly coated with a film of hard carbon and varnish. Of the ring grooves, the top ring had a very heavy carbon and varnish deposit. The second, third and fourth rings had a heavy black varnish deposit. Though the skirt of the piston appeared clean, it had some amber varnish thereon which alone is sufficient to rate the oil poor. The over-all rating of the oil of the test was considered poor and, of course, the oil failed.

From these several examples, it can be seen that the detergent properties of the material can be varied by adopting different combinations of metals and fatty starting materials. In general, the alkaline earth metals when used as saponifying agents in the fatty material will impart good detergent properties to the oil. Barium is found to be the preferable alkaline earth metal to use because it appears to enhance detergent properties to the greatest extent. Combinations of the metals, such as barium and zinc, and zinc and barium with the same fatty materials can be used, for properties can be altered according to the order in which the metals are reacted with the fatty material. By using the same metal for the saponification and subsequent neutralization, a detergent having a very high concentration of a single metal can be produced. Thus, barium, which is one of the better detergent metals, can be added to a composition to give a very high concentration of the metal. Two different metals can be used to impart slightly different properties or to balance properties and still to add to the composition a large concentration of metal. This is best exemplified by Example 4 given above wherein the barium salt of wool grease phosphorized-sulfurized zinc compound was used and found to have exceptionally good detergent properties.

It will be understood from the preceding examples that the composition contemplated is one which contains an amount of metal which exceeds that which is necessary for the neutralizatlon of the carboxyl group of the fatty material employed. Thus, a salt of any fatty acid having 12 or more carbon atoms, for example, and also containing a functional group reactable with a phosphorus sulfide, can be used as a starting material and subjected to sulfurization and phosphorization. In general, any phosphorizing-sulfurizing reagent is useful in the process, for it is not the particular reagent which is important in deriving the final product, but it is the product which has its functional group reacted with the phosphorus and the sulfur.

Thus, although the invention has been described with only a limited number of examples, they have been chosen to illustrate the several ramifications of the composition and the method of incorporating a large amount of metal therein and are to be considered as illustrative of the scope and not restrictive thereof.

What is claimed is:

1. The method of preparing a composition suitable as a lubricant additive comprising preparing a salt of wool grease and a metal selected from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt, reacting the salt with a sulfide of phosphorus at a temperature between 200 and 300 F. for a period of time sufiicient to sulfurize and phosphorize the salt, and neutralizing the sulfurized-phosphorized salt with a basic compound of a, metal of the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt, the total amount of metal reacted to form the resulting product beingsubstantially in excess of the amount required to saponify the wool grease.

2. Method in accordance with claim 1 in which the metal used in preparing the salt and for neutralizing the sulfurized-phosphorized salt is barium.

3. Method in accordance with claim 1 in which the metal used in preparing the salt is barium and the metal used for neutralizing the sulfurized-phosphorized salt is zinc.

4. Method in accordance with claim 1 in which the metal used in preparing the salt is zinc and the metal used for neutralizing the sulfurizedphosphorized salt is barium.

5. Method in accordance with claim 1 in which the salt of wool grease is reacted with phosphorus sesquisulfide at a temperature of about 240 F. while bubbling air through the mixture at a rate sufiicient to maintain the aforesaid temperature without external heating until the exothermic reaction is completed.

6. A composition of matter useful as a lubrirating oil additive to enhance detergent properties of mineral lubricating oils, said composition being a metal salt of fatty material having 12 to 30 carbon atoms in the acid radical and a metal from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt, which salt has been chemically combined with a sulfide of phosphorus at a temperature of ZOO-300 F. and then neutralized with a basic compound of a metal from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt, said composition containing an amount of combined metal substantially in excess of the amount required to saponify the fatty material.

7. In the method of preparing a lubricating oil additive, the steps of reacting a salt of a metal from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt and a fatty acid having from 12 to 30 carbon atoms in the molecule and a functional group reactive with a sulfide of phosphorus, with a sulfide of phosphorus and subsequently neutralizing the phosphorized-sulfurized material with a basic compound of a metal from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt, the weight per cent ofmetal in the neutralized material being substantially greater than that in said salt.

8. In the method of preparing a lubricating oil additive, the steps of forming a salt of a metal from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt and a fatty acid having from 12 to 30 carbon atoms in the molecule and a functional group reactive with a sulfide of phosphorus, reacting said salt with a sulfide of phosphorus and subsequently neutralizing the phosphorized-sulfurized material with a basic compound of a metal from the group consisting of zinc, barium, calcium, strontium, magnesium, tin, lead, nickel, and cobalt, the weight per cent of metal in the neutralized material being substantially greater than that in said salt.

9. The method in accordance with claim 7 in which the sulfide of phosphorus and metal salt are reacted at a temperature in the range of about 200 to 300 F. and the sulfurized-phosphorized material is neutralized at a temperature 12. Method in accordance with claim 7 in which the salt is a zinc salt, the sulfide of phosphorus is phosphorus sesquisulfide and the neutralizing agent is a basic barium compound.

13. Method in accordance with claim 12 in which the salt is zinc oleate.

14. Method in accordance with claim '7 in which the salt is a barium salt, the sulfide of phosphorus is phosphorus sesquisulfide and the neutralizing agent is a basic, barium compound.

15. Method in accordance with claim 14 in which the salt is barium oleate.

16. A composition in accordance with claim 6 which is the barium salt of wool grease chemically reacted with phosphorus sesquisulfide and subsequently neutralized with a basic barium compound.

17. A composition in accordance with claim 6 which is the barium salt of wool grease chemically reacted with phosphorus sesquisulfide and subsequently neutralized with a basic zinc salt.

18. A composition in accordance with claim 6 which is the zinc salt of wool grease chemically reacted with phosphorus sesquisulfide and subsequently neutralized with a basic barium salt.

ELMER W. BRENNAN. NORMAN D. WILLIAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 22,849 Williams et a1. Mar. 4, 1947 2,420,274 Williams et a1. May 6, 1947 2,441,587 Musselman May 18, 1948 

1. THE METHOD OF PREPARING A COMPOSITION SUITABLE AS A LUBRICANT ADDITIVE COMPRISING PREPARING A SALT OF WOOD GREASE AND A METAL SELECTED FROM THE GROUP CONSISTING OF ZINC, BARIUM, CALCIUM, STRONTIUM, MAGNESIUM, TIN, LEAD, NICKEL, AND COBALT, REACTING THE SALT WITH A SULFIDE OF PHOSPHORUS AT A TEMPERATURE BETWEEN 200 AND 300* F. FOR A PERIOD OF TIME SUFFICIENT TO SULFURIZE AND PHOSPHORIZED SALT WITH A BASIC COMSULFURIZED-PHOSPHORIZED SALT WITH A BASIC COMPOUND OF A METAL OF THE GROUP CONSISTING OF ZINC, BARIUM, CALCIUM, STRONTIUM, MAGNESIUM, TIN, LEAD, NICKEL, AND COBALT, THE TOTAL AMOUNT OF METAL REACTED TO FORM THE RESULTING PRODUCT BEING SUBSTANTIALLY IN EXCESS OF THE AMOUNT REQUIRED TO SAPONIFY THE WOOL GREASE. 